Silas Cadwell stood in the doorway. He was pale but there was a familiar sneer on his lips.

Lawrence stared at him. 'You'd better have a good explanation for this!'

The Doctor jumped to his feet. 'I hope you're satisfied, Cadwell Have you even the slightest conception of what you've done?'

The smirk slid from Cadwell's face to be replaced by a look of cold fury. 'I didn't do anything, Doctor. That's the tragedy. It is you, I think, who doesn't have the slightest conception of what you have done.'

'Explain yourself, Cadwell,' Lawrence ordered.

'You've got me all wrong,' Cadwell said. He gazed at each of them in turn, fixing them with his pale stare. 'I didn't come here to resurrect the Dark. I came here to destroy destroy it.' it.'

When Nyssa woke up she felt a lot better: apart from the slightest headache and a sore throat, she felt more like her old self. She hadn't felt like this, in fact, since before the first nightmare visitation of the Dark in the TARDIS.

That, she was surprised to find, had only been a couple of days ago; to her it felt like half a lifetime. Exhausted but relieved, she swung herself from the medical couch just as Tegan came into the sickbay.

'Hey! You're looking a lot better!'

'Thank you,' Nyssa smiled.

'Let me help you up.'

'Thanks, I'm still a bit weak. But I feel so much better.

Everything's a blur in my mind, Tegan. What have I missed?'

'Quite a lot,' Tegan told her. 'In fact, more than you'd think. It's a good job you're up, anyway: the Doctor says if you're up to it, you should come and hear what Silas Cadwell's got to say.'

Nyssa looked troubled. 'Cadwell?'

The meeting was convened in Lawrence's private cabin.

Lawrence sat at his desk with Stoker at his side, facing Cadwell. The Doctor, Tegan and Nyssa sat slightly apart.

'What's she doing here?' Cadwell asked when he saw Nyssa.

'Nyssa has played an important role in all this,' the Doctor explained. 'She has a right to a full and proper explanation.'

'Which you will now provide,' Lawrence informed Cadwell firmly. 'The Doctor has recommended that I order the Adamantium Adamantium to blast off without delay, but I will not give that order until l am in possession of the full facts.' to blast off without delay, but I will not give that order until l am in possession of the full facts.'

Cadwell returned the unfriendly stares with a cool indifference and a small sigh. 'Very well, Captain. I'll keep this as brief as possible.'

'Please do,' the Doctor said, with an impatient glance at Lawrence. 'We haven't much time.'

Cadwell smiled humourlessly and said, 'You might be forgiven for thinking that the story of the Dark begins on the planet Akoshemon: a world synonymous with wickedness and depravity throughout this part of the cosmos for many .

thousands of years. But you'd be mistaken.

The planet is nothing more than a toxic wasteland now, it choked on its own poison and decay. Such an end was inevitable, when one considers its beginning: because the Dark was present at Akoshemon's birth, a terrible force for evil already ancient and cursed when Akoshemon was in its primeval infancy.'

'So where did this Dark come from?' Lawrence asked.

'I don't think anyone can answer that question,' Cadwell replied. 'But some have tried. Some believe that it was sp.a.w.ned alongside the universe, that it is as old as creation.

Some believe that, before our own universe even existed, there were strange forces at large: G.o.ds, if you like - from before time began.'

The Doctor shifted uncomfortably in his seat. Cadwell looked at him and met his stare. 'You believe me, don't you?'

he asked.

The Doctor cleared his throat. 'I've heard the theories.

Legends of powerful forces for good and evil that survived the Big Bang.'

Cadwell nodded. 'The Dark is none of those. The Dark is all that remains of the void that existed before the Big Bang, the cavity in Time and s.p.a.ce, if you like, where those forces were first sp.a.w.ned. The Dark was shredded by the forces that created our universe, but it was not destroyed. For billions of years it lay spread across the universe, like the very faintest of shadows. Over the aeons it managed to reform itself, and finally coalesced amid the primal matter that became the planet Akoshemon.'

'A rather unfortunate start for a world.' the Doctor commented grimly.

'The worst! Akoshemon became a planet where evil flourished and grew, where every civilisation was locked into a downward spiral of corruption and destruction, war after war, atrocity on atrocity. Over the millennia, the wretched people of Akoshemon systematically injured, slew and desecrated every last one of their own kind. Eventually all that was terrible about the planet was distilled into a single, living being: the Dark personified.'

'Excuse me,' said Stoker, 'but how, exactly, did you find this out?'

Cadwell had lost his habitual sneer; in its place was a look of the gravest concern. He had spoken quietly but pa.s.sionately, and there was no mistaking the intensity in his eyes. 'The culmination of Akoshemon's vile history was a physical form for the Dark: the first it had ever known. A thousand years ago, a band of s.p.a.ce explorers discovered the planet Akoshemon at the very depths of its journey into h.e.l.l, and fell into conflict with the deadly evil at its core.'

'At first my ancestors were caught in a simple fight for survival as they became prey to the malignant forces Akoshemon had sp.a.w.ned in the name of darkness.

Gradually they became aware that this planet of destruction was a sad and terrible victim of something far worse, something rotten and vengeful that lurked in the darkness like a demon.'

'At first they could not find it, because it had no lair: its tumescent evil existed outside the natural physical laws of the universe, like an abscess on reality. But its effects were all too apparent: greed, hunger, strife, violence, betrayal...

everything that is awful and evil to us. Eventually they tracked it down, and found it in the shadows. The being they sought concealed itself there, living at one with the darkness. They called it simply the Dark.' the Dark.'

'The Dark knew our universe only through the complete absence of light. In time my ancestors cornered the beast and burned it. The flames were entirely beyond its ability to withstand.'

'A very old remedy for a very old illness,' commented the Doctor.

Cadwell gave one of his thin smiles. 'Destroyed in our physical universe, the Dark left physical remains: its ashes.

These were taken and buried deeply in the moon of the benighted world the Dark had poisoned to death. Stupid, really: Cadwell's eyes hardened into the colour of flint.

'Because it wasn't enough: the Dark's physical form was destroyed, without question, but its mind mind lived on. Trapped within the ashes, of course. But it knew there was still a chance of life, of freedom. All it required win the blood of its enemies. The blood of human beings to act as a glue to join together the burnt remnants and its vile mind.' lived on. Trapped within the ashes, of course. But it knew there was still a chance of life, of freedom. All it required win the blood of its enemies. The blood of human beings to act as a glue to join together the burnt remnants and its vile mind.'

'And Professor Oldeman provided it with a means to acquire that blood,' the Doctor said. 'He used genetic material from Akoshemon and combined it with human DNA to produce a creature that could extract the blood and take it to the crypt.'

'The Bloodhunter,' confirmed Cadwell. 'A direct descendant of the mutant abominations that had bred themselves to extinction on the Dark's host world.'

'But why would Oldeman do that?' asked Nyssa. 'Surely he wasn't in league with the Dark? I thought he came here to research into suspended-animation techniques.'

'It's doubtful Oldeman really knew what he was doing,'

the Doctor said.

'I suspect he was being influenced by the Dark.' The Doctor lowered his head. 'I was foolish not to have seen that.

I made Oldeman go to the crypt to see the result of what I thought was his cra.s.s stupidity. And the Bloodhunter killed him.'

'You can't hold yourself responsible for that!' Tegan protested. 'It could have been any one of us.'

'Is that supposed to make me feel better?'

'His blood was the final ingredient the Dark required,'

said Cadwell.

'Don't talk about Oldeman's stupidity! You, Doctor, are a fool among fools! And your foolishness did not end there.'

The Doctor looked up bleakly at Cadwell but said nothing. Cadwell's eyes were stony but they still held a gleam of real fear.

'I said earlier that I was here to stop the Dark from being reborn,' Cadwell continued. 'I knew soon after my arrival here that the beast must be perilously close to full resurrection: as the blood congealed in the ashes, it would both bind the Dark's physical remains and give them new life. It was my intention to locate the crypt and administer a powerful anticoagulant to the contents of the pit.'

'Preventing the blood from congealing any further,' Nyssa realised.

Cadwell began to pace the room and the Doctor lowered his gaze once more.

'It might not have destroyed it,' Cadwell admitted, 'but it would have given me time to consider what to do next. It might even have saved some more lives, although in truth that was not my immediate concern.

'Then it should have been,' said Tegan hotly. 'A lot of good men died down there unnecessarily.'

Cadwell gestured toward the Doctor. 'Look to him for an apology, my dear. I was interested only in halting the Dark's evil resurrection. He He prevented that.' prevented that.'

The Doctor sprang to his feet. 'You should have said so before! Why didn't you tell us what you were here for in the first place? What you already knew? What you were intending to do!'

Cadwell shook his head. 'You are all blind fools under the power of the Dark. Only I can see what had to be done. How could I trust any single one of you with the details of my task?'

'It's not like that,' the Doctor said sharply.

'It is,' replied Cadwell. 'You know it is. You know the Dark has been trying to affect your own mind, Doctor, don't you?'

The Doctor didn't reply.

Cadwell said, 'It held your friend Nyssa in its thrall. Not even I realised just how much she was being influenced by its black presence in her mind. Perhaps I should have realised, when she kept on attacking me and trying to prevent me from reaching the crypt. The Dark knew what I intended, recognised me as a threat, and used Nyssa to try and stop me just as I was using her to help me.'

Nyssa lowered her head in shame. The Doctor grew more and more angry, striding across the room to stand before Cadwell. 'Nyssa and I are more attuned to the telepathic qualities of the Dark, it's true...'

'You mean more susceptible,' said Cadwell.

'But Tegan isn't so affected - nor is Captain Lawrence or Stoker?

'Perhaps not. But they are all loyal to you, you, Doctor. Don't you understand? How could I trust anyone who might be loyal either to you... Doctor. Don't you understand? How could I trust anyone who might be loyal either to you... or or to the Dark?' to the Dark?'

Breathing heavily the Doctor stepped back. He seemed to have to make an effort to control his temper before speaking again. 'Be that as it may, Cadwell, we still have a duty to stop the Dark.'

'It's too late!' Cadwell protested. 'The Dark is free. There is nothing we can do. In time it will break into the laboratory complex and the upper cave system. If we are still here when it does, then every single one of us will be consumed by its evil will. We will be utterly destroyed.' Cadwell turned slowly, meeting the gaze of every single person in the room. 'Our only chance for survival is to leave, now .' .'

Chapter Eighteen.

Cadwell turned to Lawrence. 'Captain, you must prepare the Adamantium for immediate blast off.'

Lawrence climbed slowly to his feet, almost wearily, and when he was standing he gazed narrowly at Cadwell before saying, 'You've never given the orders on my ship, Cadwell.